The present disclosure relates to a multiple parameter sensor/transmitter-receiver unit which may be installed on or removed from an energized electric power line, such as an overhead power line. With the advent of Smart-Grid applications for electric power systems, there is an ever increasing need for a device that measures electric, mechanical, and environmental parameters of the power line.
In order to address the increasing need for monitoring power lines, devices have been developed that attach directly to the power line. These devices generally require a power source, such as batteries or solar panels. When utilizing batteries, regular maintenance must be performed to replace the batteries, which can become costly. When solar panels are used, the device may only be powered during sunny weather conditions and during daylight hours. Therefore, there is a need for a device that is powered from the current flowing in the electric power line conductor.
Additionally, utility companies invest significant capital into power systems and want to protect that investment from damage that could occur during faults, such as when trees fall onto power lines. Many prior art devices are capable of measuring current. However, the prior art devices require a coil winding to completely surround the power line to measure the power line frequency load current or fault current of the power line. This requires the power line to be disconnected to slip the coil around the power line, or a complex bending mechanism that bends the coil completely around the power line during installation or unbends the coil during removal which can lead to failure of the coil windings. Therefore, there is a need for a device which is low maintenance and can be constantly powered from the electric power line independent of weather conditions and still provide accurate current data without phase shift or saturation which is representative of the status of the power lines that is not susceptible to failure. Also, there is a need for a device that determines the direction of the fault current which may be opposite to the direction of the power line frequency load current, as well as a device that measures the high magnitude and high frequency of lightning stroke currents, and their location.